In the "why didn't I think of this" category, there are the new green colored Velcro Plant Ties. Velcro lasts forever and is easy to open and close. When your plants get a little bigger, just give the Velcro tie a little more room. It can be used again and again. HG and I tried it on an espalier apple tree and it was easy and efficient. Cut it to the size you want.
Strong and Adjustable! Self-gripping - no knots! Cut plant tie to required length, allowing for a minimum of 2" overlap.